Which feature should you use?

You have two views named Sales.SalesSummaryOverall and Sales.CustomerAndSalesSummary.
They are defined as follows:

CREATE VIEW Sales.SalesSummaryOverall
AS
SELECT CustomerId, SUM(SalesTotal) AS OverallTotal
FROM Sales.SalesOrder
GROUP BY CustomerId

GO

CREATE VIEW Sales.CustomerAndSalesSummary
AS
SELECT Customer.Name, SalesSummaryOverall.OverallTotal, (SELECT AVG(OverallTotal)
FROM Sales.SalesSummaryOverall
WHERE SalesSummaryOverall.CustomerId = Customer.CustomerId) AS avgOverallTotal,
(SELECT MAX(OverallTotal) FROM Sales.SalesSummaryOverall
WHERE SalesSummaryOverall.CustomerId =Customer.CustomerId) AS maxOverallTotal,
FROM Sales.Customer
LEFT OUTER JOIN Sales. Sales.SalesSummaryOverall
ON SalesSummaryByYear.CustomerId = Customer.CustomerId
GO

You have been tasked to modify the Sales.CustomerAndSalesSummary view to remove references to other views.
You need to identify a feature to use in the modified version of the Sales.CustomerAndSalesSummary object to achieve the task.
Which feature should you use?

A.
Table variables

B.
Temporary tables

C.
User-defined table types

D.
Common table expressions